If distortion doesn't become an issue and FR is not littered with narrow spikes and dips, who says we cannot turn a turd into something amazing?

If you have ever tried a Beyerdynamic T1.3 with and without Oratorys EQ, you will know how truly powerful that tool is!

Sure, as long as you’re not trying to make the driver do something it’s just not capable of doing (like flat subbass to 20hz on a Koss KSC75 or something) junky stuff can often be dramatically improved. It’s even kind of a fun thing to do, if you’re a weirdo like me.

That's not a story the Jedi would tell you

If the recent flood of cheap ChiFi headphones is anything to go by, tuning goes a long way in making cheap sound good

Because you can't add (with EQ) what's not there. Remember, a FR plot is not the entirety of a sound signal, it's just one way to measure some of a sound signal.

(can't I EQ a tweeter to sound like a sub? I mean it's just frequency right?)

I love how disliked this take is, especially by people who don't do things with sound for a living. Talk to any acoustician, audio engineer, mixer, etc and they all understand my point as if it's common knowledge.

TL;DR: It is possible… but not really.

There is a few reasons. The first is the variance that occurs between products of the same model. Basically even headphones of the sane model still don’t sound exactly the same. Secondly, auto EQing to a target is fairly inaccurate in the treble frequencies (I don’t know why. It’s just something that I and others have noticed). Lastly, drivers have limitations. Not all drivers are capable of delivering specific FR without audibly distorting. I’m also sure that there is some limitations to how headphones are currently measured in terms if datapoints as well. There is a lot.

[deleted]

The treble measurements are inaccurate as they are highly related to your own HRTF.

It might not sound like a high end headphone, but the sound can be incredibly improved by EQ. Even to a point that "audiophiles" would tell you that sounds like crap to justify their super expensive headphones.

A lot of the "turd" headphones require pretty serious boosts and cuts to hit your response target, and the stronger the adjustments are the more distortion you'll get. In addition there is also physics to account for so if the driver is rattling at high volume there isn't really any way to compensate for that.

For an extreme example try processing a set of free/cheap airline earbuds. You'll soon realize that if you crank the bass, all you'll get is mud as the driver simply can't reproduce those sounds. Ditto for the highs, all you'll get are harmonics on lower frequencies. And even if the midrange by design already hits your target curve, it'll still sound horrible as the driver distorts the original signal. Flat frequency response does not equal faithful reproduction!

Shelf filters are generally ok but if you’re tuning the treble then good luck…

Why can't I just paint my Toyota Corolla red and have it drive like a Ferrari?

Why is this disliked? People can't accept their $20 iem can't sound like a $1000 one?

Every driver can deliver any FR you can imagine. You just have to lower the volume. Drastically...

I feel like this should be a required reading for new users at this point. Tl;dr: It's impossible to measure what a headphone sounds like to you. Even the same headphone will sound differently between listens due to varied positions on your head. That's the fundamental problem, before even accounting for driver capability.

https://www.reddit.com/r/oratory1990/comments/gbdi7v/after_eqbeats_solo_pro_is_the_best_headphone/fpay3b5/

Harman Schmarman. Eq is Eq. My dads Sanyo had presets in the late 80s. It was great to mess around with. 99.9% of people that hear music don't know Mr Schmarman. Slide those things up or down until its suits your fancy. Then change your mind the next day. But always be thankful that you have the option to do so.

Question to OP : how can we EQ to the harman curve and be sure about it ? I mean us mortal can enthusiasts ?

Well in the traffic jam each morning during commute both cars are driving the same and you won't be faster with the Ferrari.

You are right that you can not magically have an EQ add something out of thin air that wasn't there before.

But the question of OP was if you can tune suboptimal frequency curves to match a "known good" curve.

Between 20-22k Hz there are hardly any frequencies that "whatever headphone in question" ist NOT able to reproduce AT ALL. Contrary to what you say we are not in home Cinema and try to make a tweeter from a sub.

You will have dips and bumps and the EQ will tune down the bumps and push up the dips.

In regards to music the frequency range in question is much closer to 34-18/19k Hz for the most parts and most people.

When I posed the original question I was actually thinking more along the lines how could I, for shits and giggles, add EQ to tune my HD660s to sound more like my Sundara. Then I thought if could accomplish that why not go all the way and see what the experts think about tuning turd to treasures. It’s an interesting conversation and I’m really enjoying reading the responses.

>auto EQing to a target is fairly inaccurate in the treble frequencies (Idon’t know why. It’s just something that I and others have noticed)

2 main reasons, first is that popular measurment systems are inaccurate past 10K (that might be fixed with B&K 5128 adoption), and second one is HRTF, treble can differ drastically, depending on a person. You can't really fix second one without measuring your personal HRTF.

>But the question of OP was if you can tune suboptimal frequency curves to match a "known good" curve.

That's not how I read it. "If we can tune a headphone to a harmon target, why can't we use the same device to make a crappy headphone sound like a great one." is (to me) a statement not about making a crappy headphone match the harmon target but to make a crappy headphone sound like a good headphone. Subtle but different.

I was using the tweeter/sub comparison as an extreme example. The fact is that EQ isn't free, there are phase shifts at EQ points, and extreme EQ moves (especially bell curves with tight Qs) produce artifacts at their limits. This is common knowledge when talking to people who EQ rooms for a living, one of the reasons we are going to woven projection screens is that there is less EQ that needs to be applied to a speaker array to make up for the transmission through the screen than needs to be applied for acoustic perf.

This is also why even with great examples like the UA Audio Sphere you can't exactly match all microphones. And to be clear, in that comparison you are using a great headphone to match all other headphones including crappy ones, not a crappy headphone to match a great one.

So yes, the analogy was limited but it still suggests what's going on: Firstly that there are things not in a FR plot that are acoustically important, and Secondly that it's not as simple as using an EQ to make one curve match another, because in some cases the sonic information isn't there to be boosted, and in some cases doing so to the degree needed creates other problems that can not be ignored (or fixed).

Technically this statement is no different than "can I EQ a crappy microphone to sound like a great microphone?" and everyone has already tried this. It's constantly being tested and attempted because it represents such a potential change in the recording industry. No one has got there, and there is a huge economic incentive to get there, much more than EQing headphones.

There are a lot of more technical limitations that just don’t really change based on frequency response tweaks. However, tonality is a very big part, and you can often adjust a bad headphone quite a bit with EQ before you start getting distortion, and it really does turn into something good, though I’d argue it won’t get to great.

Ultimately, you can have 2 headphones that essentially measure the same, but still sound/present the sound quite differently.

The absolute best value approach in my opinion is to get a headphone in your budget with the best technical abilities/detail and presentation style that you want, and then “fix it” with EQ.

I think you meant treble measurements, not terrible measurements.

What I still don’t get or know: how accurate are these curves, provided measurements are beyond the threshold for what is considered “okay”? The are smoothed to a portion of an octave, does that introduce small inaccuracies or not? Or is that the reason why people tell you to adjust to a curve and than modify to taste?

There's more to sound than frequency response

I lean pretty hard to the objective side and I've listened to people who are more extreme and I have literally never heard anyone disagree with what you said.

I wish I could so I could buy the comfiest headphones out there.

Even with oratory's EQ presets as in all profiles from the same source all my headphones sound quite noticeably different. HD598, DT1990, Hifiman Arya SE and the samsung galaxy buds+ after EQ.

They're closer to each other with EQ but every time I swap to the Beyer DT1990 from the Arya and vice versa I notice that the DT1990 has more micro details in bass instead of being this big slam. In addition the DT1990's electric guitars sound a bit muffled in comparison and with some specific music the soundstage just isn't there. The HD598 really lacks in micro details in bass. The Arya not nearly as much.

These aren't huge differences but noticeable enough for me to swap between both every once in a while to spice things up.

Bass comes with distortion so you can't elevate bass and expect no penalty for it. In this case EQ is a trade. You weigh the pros and cons. Sometimes getting more of muddy bass is not your preference. Leakage from long hair and glasses can worsen it. People tend to say that distortion doesn't matter in headphones, but they really mean that within reason. Distortion at bass can be very high and if you add to that leakage it means that your driver has to wobble outside of it's linear region. Such was the case of Sennheiser PX100, which had speaker level of distortion in the bass and consequently lacked the clarity of it's direct competitor, Koss Porta Pro. It's worth noting that the Koss generally sucks in it's upper range, which is why I personally never respected that headphone either.

Midrange and highs can have problems related to phase and personalisation. They often have very sharp peaks that drift in frequency from person to person. Good luck with notching them accurately! That's because the frequency of modes in the cavity between your eardrum and the driver varies with volume. If you have wider head, the driver will be pushed closer to your eardrum. If you have bigger ears, they'll displace more volume. Your ear canal entry can vary too.If you study B&K 5128 patent, you'll see that there is no one ear impedance. There is a range of ear impedances. That's OK for broad humps. Not OK for undamped resonances.

Back to the peaks and nulls in the highs. It's not easy to fix them and sometimes impossible when the mode is out of phase and cancels the otput from the driver. In such case the sound literally cancels itself and no matter how much you crank the volume up, it still is near zero dB. The only remedy is to physically address that mode in the earcup or the driver. A null like that will result in decreased detail and is an example of non-minimum phase behavior in headphones that is usually not talked by reviewers such as Crinacle, because it makes the topic too convoluted for non-engineers.

Sample variation can be an issue. You need the manufacturer to have at least some decency and do consistent QC and driver matching. On top of that the driver has to have the potential to compress air at low frequencies and have optimised modal behavior on both sides of the earcup.

That being said there are some cheap headphones that do most of that well. Long forgotten Philips models that are still in circulation on used market can be EQed to some success, but you need to make your own curve and I think this is the most important part - nobody cares about cheap headphones enough to work on EQ for them. They suck in more ways than just sound. Build quality and comfort for example. Some of them do one thing well. Aiwa Shellz comes to mind :) Can you make the upper range beautiful on those cute little buggers? Absoulutely. Can you make it play bass? Absolutely not.All in all when you EQ a headphone, it's better to be on the safe side and only add low Q filters. You'll avoid making things worse.

It works for the orks.

I understand it a little bit different obviously.

Imo applying the Harman Curve to a headphone is no different than running Audyssey or Dirac on your Stereo (or surround) setup.

Of course it is a little bit different because for a stereo setup the Speakers sound different depending on the placement. A speaker in a corner will be louder than a speaker placed against only one wall. Moreso the lower frequencies are amplified more than the higher frequencies. Straightening this change in FR is a good thing and i think most people would agree that hearing the "correct" frequencies (aka "as the artist intended") is better than hearing the unadulterated "original" speaker sound.

However the part of straightening the FR is the same for headphones. ...To an extent at least.

Because then there is a reason why all the Sennheisers and Hifimans do not play back a perfectly flat curve when measured off the factory. (And neither do any Speakers that are high rated and desired by enthusiasts.)

Recording and/or mixing equipment is inherently different in itself. This is why you are wrong with the microphone analogy. Yes, you can plug a headphone into a microphone port and even record something. But a headphone is designed to to play back what a microphone is designed for- recording this playback. This means that the merits and effects of changing a recording versus changing a playback curve are not really comparable.

Let me introduce an analogy about a different kind of reproduction. I work with printers, but also when "base lining" other devices, like TVs or Projectors, that reproduce color (in contrast to sound) you are limited by the weakest link. When you want a couple of devices to produce the same colors you test which device has the smallest color range and then tune down the other devices to this base line. You can only go "so" black for example and you can not make the brighter TV go darker, you have to brighten up the darker screen.

When comparing two speakers or headphones against a "known good" and/or desired FR and sample A has a dip at let's say 4k and the desired curve has no dip there this frequency IS THERE, its just "less loud". It is played back and you CAN add it, contrary to the color analogy. I agree that, applying an EQ has some effects on the signal and there are of course physical limits with the actual driver and at some point the driver can not "go higher" and will distort the signal there is a beautyful thing in it. Because you can just stop applying the EQ at a point before distortion and effects start occuring. And at normal listening levels you can do a lot of EQ or DSPing before a human ear will be able to make out differences that are actually caused by "physical distortion of the driver"... Unless we are talking about 1$ airplane earbuds. Then maybe... ;)

You may not be able to match 100% of any given target curve every time, but you can try to get as close as possible. So why not do it?

You should be EQing things, I'm not saying you shouldn't. We can disagree about the details, that's ok but microphones and speakers are the same devices with the same limitations.

Is the CIE 1931 color space chromaticity diagram the entirety of a projected image?

You are right

A lot crappy headphones are just muddied with bass. Remove a lot of that bass and the overall detail retrieval will still be bad. It’s really just the distortion that EQ makes by adding volume to certain frequencies. One section will ruin the sound for the rest of the spectrum. That’s why tuning is important as you will hear the most resolution the driver can provide without distorting the whole thing with EQ

EQ will alter the phase response of a headphone, therefore affecting the imaging negatively.

Yeah, sure we can. :)

I have no idea what you are talking about with the CIE question.